Method of manufacturing twisted wire products

ABSTRACT

A method of manufacturing twisted wire products having a core and at least one outer layer of wires laid about the core consists in arranging the outer layer of wires in two groups during manufacture; one group, which is a substantial fraction of the number of wires in the outer layer is twisted and disposed in contact with the core so as to form as many peripheral gaps as there are remaining wires other than those in the fraction; the second group of wires which are the remaining wires are disposed in periphearl gaps so formed, and laid radially away from the core and in contact with adjacent wires of the first group; the outer layer so arranged in two groups is subjected to radially compressive deforming forces so as to wedge the conductors of the second group into the peripheral gaps so as to produce a tight and improved twisted wire product. Circular wires of the same diameter may be used for the core and the outer layer. Twisted wire products having a plurality of outer layers may be produced by forming single outer layers as said and building them in succession; alternatively, the product may be formed in a single stage of plastic deformation and subsequent thermal treatment as required. The core may be of circular, oval, oblong or triangular shape.

United 1 States Patent Glushko et al.

[ Dec, 18, 1973 1 1 METHOD OF MANUFACTURING TWISTED WIRE PRODUCTS [76]lnventors: Mikhail Fedorovich Glushko,

prospekt Shevchenko, 15/5, kv. l7; Viktor Klementievich Skalatsky,prospekt Gagarina, 2, kv. 21, both of Odessa, USSR.

22 Filed: Dec. 7, 1971 211 App]. No.: 205,664

Primary Examiner-Donald E. Watkins Att0rney-Holman & Stern [57] ABSTRACTA method of manufacturing twisted wire products having a core and atleast one outer layer of wires laid about the core consists in arrangingthe outer layer of wires in two groups during manufacture; one group,which is a substantial fraction of the number of wires in the outerlayer is twisted and disposed in contact with the core so as to form asmany peripheral gaps as there are remaining wires other than those inthe fraction; the second group of wires which are the remaining wiresare disposed in periphearl gaps so formed, and laid radially away fromthe core and in contact with adjacent wires of the first group; theouter layer so arranged in two groups is subjected to radiallycompressive deforming forces so as to wedge the conductors of the secondgroup into the peripheral gaps so as 1 to produce a tight and improvedtwisted wire product.

Circular wires of the same diameter may be used for the core and theouter layer. Twisted wire products having a plurality of outer layersmay be produced by forming single outer layers as said and building themin succession; alternatively, the product may be formed in a singlestage of plastic deformation and subsequent thermal treatment asrequired. The core may be of circular, oval, oblong or triangular shape.

3 Claims, 16 Drawing Figures SHEET 2 BF 3 PATENIED DEC 1 8M5 METHOD OFMANUFACTURING TWISTED WIRE PRODUCTS BACKGROUND OF THE INVENTION 1. Fieldof the Invention The present invention relates to production of cablesand wire ropes and more particularly it relates to methods ofmanufacturing cables, cable strands and cores, armour of electricconductors and cable conductors, bimetallic cables of the aerial powertransmission lines and other similar twisted wire products.

2. Description of Prior Art Known in the art are the methods ofmanufacturing cables (Authors Certificate No. 55676. Cl.2l USSR) and wire ropes (Patent No. 794411, Great Briatin) comprising twisting of wireelements and their subsequent plastic reduction in thetwisted state bydrawing them through a reducing device.

Also known in the art is a method of manufacturing multiple rope strands(Patent No. 887963, Cl.84/4/, Great Britain) in which one or more layersof wire are laid about a core made in accordance with the abovementionedPatent No. 79441 1 and are subjected in succession to plastic reduction.

In all the known methods of manufacturing twisted wire products theprocess of plastic reduction is applied to the elements that have beenfully shaped in the course of twisting to a final shape, and, plasticreduction can be used either for twisting the fully shaped elements intoa wire rope or as a separate product.

However, manufacture of wire products by these above described methodsrequires considerable forces for the deformation of wires during plasticreduction of the fully shaped elements.

The need for strong forces during plastic reduction is attributablefirstly to the fact that plastic reduction is performedon the finishedelements that have already acquired .a final shape; secondly, thereducing device actssimultaneously and almost uniformly on all the outerwires when a round strand is drawn through a round pass, or on severaladjacent wires of the outer layer when a round strand is reduced to ashaped profile. Inasmuch as all the wires of the product subjected toreduction occupy strictly definite places in accordance with theirinitial dimensions and cannot there fore be displaced relative to oneanother, and also in view of the fact that the reduction forces areapplied uniformly along the entire external contour of the product or atleast along the larger part thereof, there is a very small degree offreedom for lateral deformation of wires and displacement of thematerial, ap-

proaching the state of all-round lateral compression so that theirdeformation calls for strong forces that grow with the increasing degreeof product reduction. In

practice, at the highest degrees of reduction of such products, limitedby their tensile strength during drawing through the reducing device,the wires retain rounded faces even after repeated reductions and thefinished product contains hollow spaces inside, not filled with metal.

In known prior art methods, the number of the wires in the finishedproduct and the size of wires in the product are selected to suit thediameter, construction and twisting procedures used in making saidproduct.

Thus, the manufacture of the products by the abovementioned methodscalls for the use of a large number of different wire sizes.

SUMMARY OF THE INVENTION An object of the present invention resides inproviding a method which would diminish the reducing forces in themanufacture of twisted wire products.

Another object of the invention is to provide a method accepts lesseraccuracy of the size and shape of the wires that make up the product anddiminishes the number of different wire sizes required for the productmanufacture.

Still another object of the invention is to provide twisted wireproducts manufactured by plastic reduction, the manufacture beingsimplified without sacrificing product quality.

Hereinbelow is described a method of manufacturing twisted wireproducts, e.g. wire ropes and cables made up of a core and at least onelayer of external wires disposed surrounding the core, said methodconsisting in twisting the external wires, and subjecting them toplastic reduction by drawing through a reducing device. According to theinvention, some of the wires in the external layer are so located priorto end during twisting that they stand out radially above the adjacentwires of said layer after; the wires so arranged surrounding the coreare reduced by applying pressure of a reducing device, pressure beingapplied particularly to the protruding wires thereby wedging and forcingthem in between the adjacent wires.

It is practicable during the manufacture of twisted wire products havingtwo or more layers to have some of the wires in each layer protrudingabove the adjacent wires, that the layers are subjected to plasticreduction successively, one after another.

Owing to the use of the claimed method in a twisted wire product, if thewires of the product were replaced by round wires of equivalent crosssectional area, retaining the principle of mutual contact, at least oneof the wires in the outer layer would stand out above them, protrudingbeyond an imaginary contour envelope described around the wires of theouter layer disposed around the core.

The method described and claimed herein requires reduced forces for theplastic reduction of the product due to the employment of the wedgeeffect produced by the specific arrangement of the wires in the product.

The method increases the maximum dimensions of the products subjected toplastic reduction at a given degree of reduction or increases; thedegree of reduction with the use of the same equipment.

The claimed method also ensures a high degree of filling with metal, ofthe cross sectional area of the product subjected to plastic reductionby means of comparatively small reduction forces.

The method of manufacturing twisted wire products described hereindecreases the demands for the accuracy of wire sizes in the productssince the geometrical nonconformity of these sizes with the placeassigned for the wires in the product is compensated for by lateraldeformation of the wires and by the redistribution of the wire materialin the course of product shaping.

Besides, the claimed method tolerates a reduced accuracy of thedimensions and shapes of the product wires and the number of wire sizesrequired for manufacturing a single product.

The method of the present invention makes it possible to reduce thedegree of nonuniformity of the mechanical properties of the products bystandardizing the conditions of production and employing more rationalprocedures for the mechanical and thermal treatment of the wires whicheventually improves the quality of the products.

The reduction of the total number of wire sizes in manufacturing theproducts of the same type simplifies the organization of theirmanufacture, cuts down the time required for refitting the equipment forother wire sizes, and simplifies the work related to the supply andstorage of tools.

The claimed method is advantageous for devising new an improvedstructure of the products to suit the operational demands.

BRIEF DESCRIPTION OF THE DRAWINGS Now the invention will be described indetail with reference to the drawings, in which:

FIG. 1 shows an arrangement of the wires in an outer layer of theproduct before plastic reduction;

FIG. 2 shows the arrangement of the wires in the outer layer of theproduct of FIG. 1 after plastic reduction;

FIGS. 3 and 4 show the cross sectional areas of the product,construction 1+6, before and after plastic reduction, respectively;

FIGS. 5 and 6 show the cross sectional areas of the product,construction 1+7, before and after plastic reduction, respectively;

FIGS. 7 and 8 show the cross sectional areas of the product,construction l+6+l2, before and after plastic reduction, respectively;

FIGS. 9, 10 and 11 show the cross sectional areas of the product,constructions 1+8, l+5+l0 and l+7+14, respectively, before plasticreduction;

FIGS. 12 and 13 show the cross sectional areas of the multiple-layerproducts before subjecting them to plastic reduction as a whole andlayer-by-layer, respectively;

FIGS. 14, l5, 16 show the cross sectional areas of the products of oval,triangular and flat shapes, respectively, before plastic reduction.

The claimed method is put into operation as follows.

The wires selected in number to suit the dimensions, shape, constructioncharacteristics and other requirements of the product are twisted sothat some of the outer layer of wires 1 (FIG. 1) are located on the core2 of the product and is inscribed into the imaginary contour or envelope3 while some of the wires 4 of the outer layer are located in the spacesbetween the adjacent wires 1 and stand out radially above the wires 1,protruding out of the envelope 3.

The core 2 is the center of the product construction. The core mayconsist of one or more wires, a singlelayer or multiple-layer wirestrand or any other member of sufficient strength, and suitable shapeand dimensions.

The wires assembled in the above-described manner are then subjected toplastic reduction by drawing through a reducing device (not shown in thedrawings). The reducing device sets on the protruding wires 4, forcingthem between the wires 1 with pressure P.

Owing to such a relative arrangement of the wires, the external pressureP applied to the protruding wires is transmitted in the form of pressureS to the adjacent lower wires 1 at the point of the contact surfaces 5,the direction of the pressure S being inclined to the direction of theexternal pressure P at angle a which produces a certain amount of wedgeeffect during the transmission of forces. Under conditions ofequilibrium of the protruding wires 4, the wedging pressure S will S P/2sina It follows from the above that by selecting certain ratios betweenthe dimensions of the wires 1 and 4 and the distance between the wires 1it becomes possible to ensure a sufficiently small wedging angle a forobtaining comparatively strong wedging pressures S. This createsconditions for easier penetration of the protruding wires 4 into theenvelope or contour 3 of the product.

As the protruding wires 4 penetrate into the contour 3 of the product,they become deformed, upsetting the adjacent wires 1. As a result, thewires 1 and 4 in the finished product (FIG. 2) acquire shaped profiles land 4 respectively and are located inside envelope or said contour 3 ora contour approaching its dimensions.

The reducing devices can be constituted by onepiece or sectional dies,various reducing rolls and other metalworking tools.

The claimed method can be used for manufacturing diverse twisted wireproducts, namely spiral ropes, rope strands and cores, wire armour ofelectric cables, current-carrying cable conductors and the like.

In manufacturing twisted wire products subjected to plastic reductionand containing more than two layers of wire, each layer may be shapedand reduced in succession, using the inner already-reduced portion inthe the core member for plastic reduction of the next layer.

Given below are the examples of twisted wire products manufactured bythe claimed method which, in turn, can be used as component parts ofother, more complicated products.

In FIG. 3 is shown one of the possible cross-sectional areas of theproduct, the so-called construction 1+6, wherein one central wire 6 iscovered with a layer of six wires 7 and 8. As a result of twisting, thecross sections of the wires 7 and 8 approach an ellipse while thecentral wire 6 is of a round section. Assuming that all the wires ofsuch a product are of the same size then, owing to the ellipticalsection of the wires 7 and 8, some of them protrude beyond the limits ofthe imaginary contour or envelope 9 described around the wires 7 laidabout the wire 6.

Therefore, in the known methods of making such strands, correct layingof the wires 7 and 8 is ensured by making the diameter of the centralwire 6 somewhat larger than that of the wires 7 and 8.

However, in manufacturing a product in accordance with the claimedmethod there is no need for a larger size for the central wire 6; on thecontrary, loose laying of the wires 8 about the wire 6 is utilized forwedging. For this purpose some of the wires 7 are laid around thecentral wire or core 6 inside of the imaginary contour or envelope 9.The protruding wires 8 acted upon by the reducing device function aswedges and penetrate into the contour 9 of the product into the spacesbetween the wires 7.

As a result of these operations the finished product acquires the crosssectional area shown in FIG. 4. Other arrangements of the wires in theproduct are also feasible, for example with one or two protruding wires.

EXAMPLE 2 The claimed method can be utilized for manufactur ing aproduct of construction of the so-called 1+7 type consisting ofidentical wires.

In this product a layer of seven wires 11 and 12 is laid about thecentral wire (FIG. 5). FIG. 5 shows the cross sectional area of thewires in the product of construction 1+7 with three protruding wires 11.Other numbers of protruding wires 11 are possible too. The reducingdevice makes the protruding wires 11 penetrate into the spaces betweenthe wires 12 and enter the contour 13 of the product section. After sucha power reducing treatment, the cross sectional area of the finishedproduct takes the shape illustrated in FIG. 6.

To simplify the drawings, the wires in FIGS. 5, 7, 9-16 are shown of around shape.

The proposed method can also be utilized for manufacturingmultiple-layer twisted wire products.

EXAMPLE 3 Shown in FIG. 7 is a cross section of a two-layer product, theso-called construction 1+6+l2. The wires 14 of the outer layer arelocated inside the contour 15. The wires 16 located in the spacesbetween the wires 14 protrude beyond the limits of the contour 15. Inthe prior art methods for manufacturing such constructions, theprotruding wires 16 are replaced by the wires 17 of a smaller diameterso that they contact the adjoining wires 14 and remain inside thecontour 15.

While manufacturing this product in accordance with the claimedmethod,the protruding wires 16 are forced by the reducing device into thecontour l5, transmitting pressure to the other wires. The wires 14inside the contour are upset but, due to their twisting, are not forcedout of the contour 15 but are held in place by their remaining portionthat has already been reduced and is located beyond the zone of actionof the reducing device. As a result, all the wires are deformed andchange both their cross-sectional shape, the cross section of thefinished product acquiring the shape illustrated in FIG. 8.

Because of the differences in the conditions of reduction, the wires 14and 16 in the finished product may take different cross sectionalshapes. Under some conditions of product shaping it is possible that oneor more wires of the outer layer may pass into the inner layer if thereis a certain clearance between the wires of said inner layer, this beingaccompanied by the wedging effect. The passage of the wires from onelayer into another does not impair the quality of the product.

EXAMPLE 4 EXAMPLE 5 The multipleJayer products, particularly three-layertwisted wire products, may be manufactured by two methods: either theproduct is subjected to plastic reduction in the already twisted state(FIG. 12) or it is reduced layer by layer (FIG. 13).

In the first case the role of wedges in the entire quantity of wires inthe product is played by the protruding wires 21 (FIG. 12).

In the second case each successive layer of wires is laid about theinner part 22 (hatched in FIG. 13) that has already been reducedaccording to the claimed method so that some wires of the outer layer 23protrude above the wires 24 and function as Wedges during plasticreduction.

The principle of plastic reduction utilizing the wedge effect can beused in manufacturing the products with the cross sectional areas otherthan round, for example oval, triangular, flat, etc.

EXAMPLE 6 Shown in FIGS. l4, l5 and 16 are the arrangements of the outerlayer of wires 25 and 26 laid about the core 27 of an oval, triangularand flat shape, respectively. The wires 25 are located in the spacesbetween the wires 26 laid about the core 27, protruding above them. Inthe course of plastic reduction the wires 25 are deformed themselves andsimultaneously deform the wires 26 and, in some cases, the wires of thecore 27.

What is claimed is:

l. A method of manufacturing twisted wire products, such as cables andwire ropes consisting of a core with at least one layer of outer wireslaid about said core, said method comprising the following operations:twisting and arranging said outer wires of at least one layer to disposea fraction of the number of said outer wires around and in contact withsaid core and forming as many peripheral gaps between wires so laid incontact with the core as there are remaining wires which are wires otherthan said fraction of said outer wires; locating said remaining wires insaid peripheral gaps to be radially away from and out of contact withsaid core but in contact with adjacent wires of said fraction so as toprotrude radially outwardly of the wires of said fraction; performingplastic reduction of all the twisted wires of the product by applyingradial pressure of a reducing device to the protruding wires of theouter layer and using said protruding wires as wedges forced in betweenthe adjacent wires, so as to form a twisted wire product of a desiredcross section.

2. A method according to claim I wherein in manufacturing the twistedwire products which consists of a plurality of layers, the methodincludes the step of arranging some wires in each layer protruding abovethe adjacent wires, and the step of performing plastic deformation byreduction of said plurality of layers in succession, one after another.

3. A twisted wire product comprising: a core member with at least onelayer of outer wires laid about said core member and shaped by reductionand radial compression, at least some of said wires having a noncircularcross section and substantially radial sides, whereby if the wires ofthe product were replaced by round wires of equivalent cross sectionarea, retaining a principle of mutual contact, then one half or less ofthe wires composing the outer layer would stand out above the rest ofthe'wires so as to protrude from an imaginary contour described aroundthe outer layer of

1. A method of manufacturing twisted wire products, such as cables andwire ropes consisting of a core with at least one layer of outer wireslaid about said core, said method comprising the following operations:twisting and arranging said outer wires of at least one layer to disposea fraction of the number of said outer wires around and in contact withsaid core and forming as many peripheral gaps between wires so laid incontact with the core as there are remaining wires which are wires otherthan said fraction of said outer wires; locating said reMaining wires insaid peripheral gaps to be radially away from and out of contact withsaid core but in contact with adjacent wires of said fraction so as toprotrude radially outwardly of the wires of said fraction; performingplastic reduction of all the twisted wires of the product by applyingradial pressure of a reducing device to the protruding wires of theouter layer and using said protruding wires as wedges forced in betweenthe adjacent wires, so as to form a twisted wire product of a desiredcross section.
 2. A method according to claim 1 wherein in manufacturingthe twisted wire products which consists of a plurality of layers, themethod includes the step of arranging some wires in each layerprotruding above the adjacent wires, and the step of performing plasticdeformation by reduction of said plurality of layers in succession, oneafter another.
 3. A twisted wire product comprising: a core member withat least one layer of outer wires laid about said core member and shapedby reduction and radial compression, at least some of said wires havinga non-circular cross section and substantially radial sides, whereby ifthe wires of the product were replaced by round wires of equivalentcross section area, retaining a principle of mutual contact, then onehalf or less of the wires composing the outer layer would stand outabove the rest of the wires so as to protrude from an imaginary contourdescribed around the outer layer of wires laid about the core.